Radioactive generator with permeable closure

ABSTRACT

A radioactive generator has silicone or neoprene closures to vent the gases released during the generation of radioactive eluate. The generator comprises a hollow, generally cylindrical body in which a column of radioactive material is contained, and the ends of which are closed by silicone or neoprene stoppers fabricated from material such as methylvinylpolysiloxane or polychloroprene. The generator can be subjected to sterilizing procedures such as autoclaving and retain its sterile condition, while at the same time gases generated internally may be vented through the closures.

United States Patent. 1

Hulit et al.

[451 Apr. 2, 1974 RADIOACTIVE GENERATOR WITH PERMEABLE CLOSURE 75]Inventors: Harry]. l-lulit, Amboy; Thomas V. Czaplinski, Brunswick, bothof NJ.

[73] Assignee: E. R. Squibb & Sons, Inc.,

Princeton, NJ.

221 Filed: Oct. 24, 1972 21 Appl. No.: 300,092

[52] U.S.Cl ..'.....250/496,128/1.l s11 Int.Cl. ..G2lh 5/00 [58] Fieldof Search 250/106. R, 106 T; 23/267 A, 259; 128/1.1, 1.2

[5 6] References Cited UNITED STATES PATENTS 3,156,532 11/1964 Doel'ing250/106 T 3,133,196 5/1964 Rochlin 136/89 3,369,121 2/1968 Bruno et al.250/108 R Primary Examiner-Harold A. Dixon Attorney, Agent, orFirm-Lawrence S. Levinson; Merle J. Smith; John J. Archer [5 7] ABSTRACTA radioactive generator has silicone or neoprene closures to vent thegases released during the generation of radioactive eluate. Thegenerator comprises a hollow, generally cylindrical body in which acolumn of radioactive material is contained, and the ends of which areclosed by silicone or neoprene stoppers fabricated from material such asmethylvinylpolysiloxane or polychloroprene. The generator can besubjected to sterilizing procedures such as autoclaving and retain itssterile condition, while at the same time gases generated internally maybe vented through the closures.

6 Claims, 2 Drawing Figures RADIOACTIVE GENERATOR WITH PERMEABLE CLOSUREBACKGROUND OF THE INVENTION The present invention relates to-a generatorfor the production of radioactive eluate,-and more specifically agenerator having silicone or neoprene closures to permit the venting ofgases internally generated.

The use of radioactive isotopes for the diagnosis and treatment ofvarious medical problems is well-known. Generators such as thatdescribed in U. S. Pat. No. 3,369,121, Feb. 13, 1968, are widely used inthe production of radioactive eluate. These generators are utilizedsince certain radioactive isotopes have a very short half-life and,consequently, it is necessary for the physician to prepare such isotopesas, and where, they are to be used.

An example of such an isotope is the 99m isotope technetium which isused for the localization of brain tumors. This isotope has a half-lifeof six hours and is obtained as the daughter product of molybdenum M Itis separated in the form of the pertechnetateion from M0 absorbed on analumina column, by elution with dilute hydrochloric acid or saline. Atvarious times during autoclaving, gases may be internally generated.These gases reduce the isotope yield of the generator and, in any event,must be removed for the obtainment of eluate.

Previously, the generators were closed by pierceable rubber stoppersthrough which a hypodermic needle was inserted to vent the gases. Thisis a very timeconsuming and tedious operation, and since the materialsare always undergoing fairly rapid degeneration, the yield of aparticular generator can be reduced. The present invention utilizessilicone or neoprene closures which are pervious to the generated gases.At the same time the silicone or neoprene closures may be subjected toany popular sterilizing technique such as autoclaving and resist theinflow of any bacteria. In sum mary, the silicone or neoprene stoppersare gas pervious yet maintain generator stability.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide a radioactive eluate generator which maintains sterility at alltimes.

Another object of the present invention is the provipolychloroprene. Thestoppers are pierceable so as to admit solution for the production ofthe radioactive isotope. The stoppers, however, are sufficientlypervious to vent any and all gases internally generated. Furthermore,the stoppers may be subjected to any preferred sterilizing technique,such as autoclaving, and will effectively maintain sterile conditions atall times.

The above and other objects of the present invention will be apparent asthe description continues and when read in conjunction with the annexeddrawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially cross sectioned viewof a preferred embodiment.

FIG. 2 is a perspective view of an individual closure.

DETAILED DESCRIPTION The present invention is associated with aradioactive material generator similar to that shown and described in U.S. Pat. No. 3,369,121. Briefly, the radioactive material generatorcomprises a column 10 fabricated from a plastic or similar typematerial. The column 10 has a shell 12 and is surrounded by a pluralityof integral fins 14.

The column 10 is closed by stoppers 16, 18, which are pervious to thepassage of gas therethrough and may be made from silicone or neoprene,of which more will be described at a subsequent point. Included incolumn 10 is the curvilinear partition 20 which basically separates itinto two parts, the upper part 22 and the lower part 24. The partition20 can be integral with the shell 12 or suitably attached thereto, andit tapers from section 22 toward section 24 providing a ratherrestricted opening 26 at the bottom thereof. The exact dimensions of thepartition are unimportant, however, it has been found that it shouldextend a slight distance below the top of a breather tube 28 whichpunctures closure 18, which breather tube permits the interior ofsection 24 to communicate with the atmosphere. To assure sterility, thebreather tube is fitted with a suitable filter material 30 whichprevents the flow of bacteria to the interior of the shell 12.

Positioned at the upper end of the partition 20 is a disc 32, which mustbe perforated, and on which rests a filter pad 34. At the top of filter34 is a granulated radioactive alumina 36, and optionally, a cationexchange resin such as Dowex-SO x8 to prevent the passage of the aluminathrough the column during elution. The granulated alumina 36 may beretained in place by use of a perforated disc 38 which is held in placeby a retaining ring 40.

In preparing a radioactive solution, eluent is emitted from the eluentcontainer 42 into section 22 via the hypodermic needle 44 which piercesclosure 16. The hypodermic needle 46 withdraws the radioactive solutionthat has been prepared in section 22 and passed to section 24.

As shown in FIG. 2 the closures 16, 18 are in the nature of circularplugs with a central depression 50 and a circular flange 52. Theclosures are c'lose-fittedly received within compatible openings in thetop and bottom of column 10 and are maintained in place by the covermembers 54, 56 which are preferably fabricated from ductile metals andwhich are crimped thereabout; the covers 54, 56 engage the shoulders54a, 56a permanently maintaining the closures l6, 18 in their respectivepositions in the column.

During the sterilization of the generators, particularly duringautoclaving, a substantial quantity of gases are generated in thesections 22, 24. In the past, a hypodermic needle has been inserted intotop closure 16 to vent these gases. This has proved to be a ratherinconvenient manner of venting the gases as well as consuming an unusualamount of time. The use of silicone, neoprene or like material, ascompared to the prior use of rubber, produces a number of advantages.Silicone or neoprene is sufficiently porous to permit the escape ofinternally generated gases without the use of hypodermic needles, inthat, the gases merely pass through the closure body. In addition, thesilicone or neoprene is easily pierced by hypodermic needles and isessentially completely selfsealing The particular silicone chosen ispreferably one of the organopolysiloxanes, notablymethylvinylpolysiloxane, one of the Dow Corning Silastic brand. Theseclosures are useful over a wider temperature range than any otherrubber-like material, for instance, they retain their physicalproperties in a low and high temperature range of lF to 500F andtherefore can be autoclaved. The particular neoprene chosen ispreferably polychloroprene manufactured by the Tompkins Rubber Co.

The yield of radioactive solution of any given generator is strikinglyincreased by the use of the silicone or neoprene closures. Theradioactive materials involved, have relatively short half-lives and anytime wasted venting gases results in an under utilization of thegenerator. The stoppers, therefore, not only permit the simple ventingof the trapped gases and elimination of additional hypodermic needles,but they effectively increase the yield of a given generator.

Many changes may be made in the details of the instant invention withoutdeparting from the spirit and scope of the appended claims, whichchanges are intended to be embraced therewithin.

What is claimed is:

1. In a generator containing a column of sterile elutable radioactivematerial to be utilized for diagnosis and treatment for medicalconditions, said generator of the type which comprises a hollow bodyclosed at its top and bottom by pierceable autoclavable closures andhaving positioned therein and spaced from the bottom thereof a source ofelutable, short-lived radioactive material, whereby a sterile eluateready for utilization is delivered from the body, the improvement whichcomprises said autoclavable closures being fabricated from materialwhich is pierceable, and gas pervious permitting the venting directlythrough said closures of gases formed in the generator, said closuresbeing sufficiently dense to prevent the passage of fluid directlytherethrough as well as preventing the inflow of bacteria therethrough.

2. The generator of claim 1 wherein the closures are made from silicone.

3. The generator of claim 1 wherein the closures are permanently affixedto said body to seal said body.

4. The generator of claim 3 wherein the closures are fabricated frommethylvinylpolysiloxane.

5. The generator of claim 1 wherein the closures are made from neoprene.

6. The generator of claim 5 wherein the pierceable closures arefabricated from polychloroprene.

[UNITED STA'IES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,801,818 Dated April 2, 1974 Invencofls) Harry J. Hglit and Thomg v.Czeplinski It is certified that error appears in the above-identifiedpatent andfnat said Letters Patent are hereby corrected as h balm"Urider "Inventors: "Amboy" should be 'South Amboy'- 'and "Brunswick"should be -North Brunswick--.

Column 1 line 19, --ofshould be inserted before "teohnetiom" Column Iline" 22, delete the. hyphen fol lowing "pertech netat e" Signed andsealed this 30t day of July 1971,.

( EAL) Attest:

0N JR. c. MARSHALL DANN MCCOY M GIBS Commissioner of Patents Attestin'gOfficer x

1. In a generator containing a column of sterile elutable radioactivematerial to be utilized for diagnosis and treatment for medicalconditions, said generator of the type which comprises a hollow bodyclosed at its top and bottom by pierceable autoclavable closures andhaving positioned therein and spaced from the bottom thereof a source ofelutable, shortlived radioactive material, whereby a sterile eluateready for utilization is delivered from the body, the improvement whichcomprises said autoclavable closures being fabricated from materialwhich is pierceable, and gas pervious permitting the venting directlythrough said closures of gases formed in the generator, said closuresbeing sufficiently dense to prevent the passage of fluid directlytherethrough as well as preventing the inflow of bacteria therethrough.2. The generator of claim 1 wherein the closures are made from silicone.3. The generator of claim 1 wherein the closures are permanently affixedto said body to seal said body.
 4. The generator of claim 3 wherein theclosures are fabricated from methylvinylpolysiloxane.
 5. The generatorof claim 1 wherein the closures are made from neoprene.
 6. The generatorof claim 5 wherein the pierceable closures are fabricated frompolychloroprene.